Tissue extraction and maceration device

ABSTRACT

Devices and methods are provided for extracting and macerating tissue, and optionally for depositing the tissue onto a tissue scaffold. The device generally includes an outer tube having a substantially open distal end that is adapted to be placed on and preferably to form a seal with a tissue surface, and a shaft rotatably disposed within the outer tube and movable between a first, proximal position in which the shaft is fully disposed within the outer tube, and a second, distal position in which a portion of a distal end of the shaft extends through the opening in the distal end of the outer tube. The device also includes a tissue harvesting tip formed on the distal end of the shaft that is effective to excise a tissue sample when the shaft is moved to the distal position, and a cutting member that is coupled to the shaft at a position proximal to the tissue harvesting tip. The cutting member is effective to macerate a tissue sample excised by the tissue harvesting tip.

FIELD OF THE INVENTION

The present invention relates generally to devices and methods forextracting and macerating tissue.

BACKGROUND OF THE INVENTION

Bone grafts are often used to treat fractures, gaps in bones caused bytrauma or infection, revision joint surgery, and oral/maxillofacialsurgery. Bone grafts provide a framework into which the host bone canregenerate and heal. Once implanted, the bone cells weave into andthrough the porous microstructure of the bone graft to support the newtissue, blood cells and soft tissue as they grow to connect fracturedbone segments.

The loss or failure of tissue is one of the most frequent and costlyproblems in human health care. In recent years, grafting has evolvedfrom the initial autograft and allograft preparations to biosyntheticand tissue-engineered living replacements. Tissue engineering enablesthe growth of transplantable functional tissue replacements startingfrom samples of autologous cells of the patient. The cells are obtainedby harvesting tissue from a patient using a biopsy and then cells areextracted from the tissue sample and cultured to the appropriate numbersin the laboratory. These living cells are then placed in athree-dimensional natural or synthetic scaffold or matrix, and are keptunder tissue specific culture conditions to ensure differentiation andtissue maturation. If provided with the appropriate conditions andsignals, the cells will secrete various matrix materials to create anactual living tissue that can be used as a replacement tissue to beimplanted back into the defective site in the patient.

Current tissue engineering procedures involve a multi-step process.First, a biopsy is performed to remove a tissue sample from a patient'sbody. A variety of biopsy devices are well known in the art, including,for example, high-pressure fluid jets that are effective to cut andretrieve a tissue sample. Once the biopsy procedure is complete, thetissue sample is then sent to a laboratory, where the tissue is preparedfor cell isolation. The isolated cells can then be placed into athree-dimensional scaffold for subsequent growth and eventuallyimplantation back into the patient.

While current procedures have proven effective, they can be verytime-consuming and costly. Accordingly, there exists a need for moreefficient and effective methods and devices for obtaining and processinga tissue sample. There also remains a need for an improved biopsy devicethat maximizes cell viability.

SUMMARY OF THE INVENTION

The present invention provides a tissue extraction and maceration devicethat is designed to effectively remove a viable tissue sample, tocontrol the volume of tissue removed, and to macerate the tissue sampleinto particles having a predetermined size. In general, the deviceincludes an outer tube having a substantially open distal end that isadapted to be placed on and to form a seal with a tissue surface, and ashaft that is rotatably disposed within the outer tube and that ismovable between a first, proximal position in which the shaft is fullydisposed within the outer tube, and a second, distal position in which aportion of a distal end of the shaft extends through the opening in thedistal end of the outer tube. In one embodiment, a biasing element canbe provided for biasing the shaft to the proximal position, and atrigger mechanism can be connected to the shaft to, upon actuation,overcome the biasing force to move the shaft from the proximal positionto the distal position.

The device also includes a tissue harvesting tip formed on the distalend of the shaft. The tissue harvesting tip is effective to excise atissue sample. In one embodiment, the harvesting tip can be acone-shaped member having a plurality of cutting teeth formed on anouter surface thereof. In another embodiment, the harvesting tip can bea substantially semi-cylindrical housing having a cutting surface formedaround a periphery thereof. While the harvesting tip can have a varietyof configurations, it is preferably adapted to penetrate tissue toremove a predetermined volume of tissue when the shaft is moved from theproximal position to the distal position.

The device can further include a cutting member coupled to the shaft ata position proximal to the tissue harvesting tip. The cutting member,which is preferably in the form of at least one blade member extendingradially from the shaft, is effective to macerate a tissue sampleexcised by the tissue harvesting tip. Each blade member can have a shapesuch as, for example, a rectangular shape, a curved shaped, a triangularshape, a square shape, an irregular shape, and combinations thereof.

In another embodiment, the device includes a sizing screen disposedwithin the outer tube and positioned proximal to the harvesting tip andthe cutting member of the shaft. The sizing screen can have severalopenings formed therein for allowing tissue of a predetermined size topass therethrough. The openings can optionally be defined by a wallhaving an upstream edge that is effective to cut tissue having a sizegreater than the circumference of the openings.

The present invention also provides a method for harvesting a tissuesample using a tissue extraction and preparation device having an outertube with an open distal end, and a shaft rotatably disposed within theouter tube and including a tissue harvesting tip formed on the distalend thereof and a cutting member coupled to the shaft at a positionproximal to the tissue harvesting tip. The method includes the steps ofcoupling the proximal end of the shaft to a driver mechanism, andpositioning the open distal end of the outer tube against a tissuesurface at a desired tissue sample site. The driver mechanism is thenactuated to effect rotation of the shaft within the outer tube, and theshaft is moved from a proximal position, wherein the harvesting tip ofthe shaft is disposed within the outer tube, to a distal position,wherein the harvesting tip extends distally from the outer tube, therebycausing the harvesting tip to obtain a tissue sample. The shaft is thenreturned to the proximal position wherein the tissue sample is maceratedby the cutting member. In a further embodiment, the outer tube can becoupled to a tissue dispensing device that is effective to deposit themacerated tissue sample onto a tissue scaffold.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich like reference numerals designate like parts throughout thevarious figures, and wherein:

FIG. 1A is a perspective view of a tissue extraction and macerationdevice according to one embodiment of the present invention;

FIG. 1B is a cross-sectional view of the tissue extraction andmaceration device shown in FIG. 1A;

FIG. 2A is a perspective view of the outer tube of the tissue extractionand maceration device shown in FIGS. 1A and 1B;

FIG. 2B is a cross-sectional view of the outer tube shown in FIG. 2A;

FIG. 3A illustrates one embodiment of a harvesting tip of an inner shaftfor use with a tissue extraction and maceration device in accordancewith the present invention;

FIG. 3B illustrates another embodiment of a harvesting tip of an innershaft for use with a tissue extraction and maceration device inaccordance with the present invention;

FIG. 3C illustrates yet another embodiment of a harvesting tip of aninner shaft for use with a tissue extraction and maceration device inaccordance with the present invention;

FIG. 3D illustrates yet another embodiment of a harvesting tip of aninner shaft for use with a tissue extraction and maceration device inaccordance with the present invention;

FIG. 4A illustrates one embodiment of a cutting member for use with atissue extraction and maceration device in accordance with the presentinvention;

FIG. 4B illustrates another embodiment of a cutting member for use witha tissue extraction and maceration device in accordance with the presentinvention;

FIG. 4C illustrates yet another embodiment of a cutting member for usewith a tissue extraction and maceration device in accordance with thepresent invention;

FIG. 4D illustrates yet another embodiment of a cutting member for usewith a tissue extraction and maceration device in accordance with thepresent invention;

FIG. 4E illustrates yet another embodiment of a cutting member for usewith a tissue extraction and maceration device in accordance with thepresent invention;

FIG. 4F illustrates yet another embodiment of a cutting member for usewith a tissue extraction and maceration device in accordance with thepresent invention;

FIG. 5 illustrates one embodiment of a sizing screen for use with atissue extraction and maceration device in accordance with the presentinvention;

FIG. 6 illustrates the tissue extraction and maceration device shown inFIG. 1A mated to a tissue collection device according to anotherembodiment of the present invention;

FIG. 7A illustrates a tissue extraction and maceration according to thepresent invention positioned on a tissue surface; and

FIG. 7B illustrates the tissue surface having a tissue sample removedtherefrom using a tissue extraction and maceration device according tothe present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides devices and methods for extracting andmacerating tissue, and optionally for depositing the tissue onto atissue scaffold. As shown in FIGS. 1A-1B, the device 10 generallyincludes an outer tube 12 having a substantially open distal end 12 bthat is adapted to be placed on and preferably to form a seal with atissue surface, and a shaft 14 (FIG. 1B) rotatably disposed within theouter tube 12. The shaft 14 is movable between a first, proximalposition, as shown in FIG. 1B, in which the shaft 14 is fully disposedwithin the outer tube 12, and a second, distal position (not shown) inwhich a portion of a distal end 14 b of the shaft 14 extends through theopening in the distal end 12 b of the outer tube 12. The device 10 alsoincludes a tissue harvesting tip 16 formed on the distal end 14 b of theshaft 14 that is effective to excise a tissue sample when the shaft 14is moved to the distal position, and a cutting member 18 that is coupledto the shaft 14 at a position proximal to the tissue harvesting tip 16.The cutting member 18 is effective to macerate a tissue sample excisedby the tissue harvesting tip 16. In an exemplary embodiment, thecomponents of the device 10 are positioned within an outer housing 26that extends around a portion of the outer tube 12 and that has a shapethat facilitates handling of the device 10.

The device is particularly advantageous in that it provides a simple,all-in-one device that can be operated using one hand. The device isdesigned to effectively remove a viable tissue sample, to control thevolume of tissue removed, and to macerate the tissue sample intoparticles having a predetermined size.

The outer tube 12 of the device 10, which is shown in more detail inFIGS. 2A and 2B, can have virtually any shape, size, and configuration.In the illustrated embodiment, the outer tube 12 has a generallyelongate cylindrical shape and includes proximal and distal ends 12 a,12 b with an inner lumen 12 c extending therebetween. The proximal end12 a of the outer tube 12 can be open or closed, but it is preferablyadapted to connect to a driver mechanism, as will be discussed below.The distal end 12 b of the outer tube 12 is at least partially open andit can be adapted to rest against a tissue surface. The distal end 12 bcan further have a shape that is configured to provide a seal betweenthe inner lumen 12 c of the outer tube 12 and a tissue surface. As shownin FIG. 2B, the distal end 12 b of the outer tube 12 is disposed at anangle α with respect to a longitudinal axis L of the device 10. Whilethe angle α can vary, in an exemplary embodiment the distal end 12 b isangled in the range of about 30° to 70°, and more preferably at about40° with respect to the axis L. In use, the seal created between thedistal end 12 b and the tissue surface is particularly advantageous inthat it will prevent foreign matter from entering the inner lumen 12 cof the outer tube 12. While an angled distal end 12 b is preferred, thedistal end 12 b of the outer tube 12 can have a variety of otherconfigurations, and it can optionally include other features tofacilitate placement on and/or a sealed connection with a tissuesurface. By way of non-limiting example, the edge wall on the distal end12 b of the outer tube 12 can include surface features, such as ridges13, formed thereon to facilitate the secure positioning of the outertube 12 on a tissue surface. A person skilled in the art will appreciatethat other techniques can be used to help maintain the position of theouter tube 12 on a tissue surface.

In another embodiment, the outer tube 12 can include a sidearm 20 formating the device 10 to a tissue collection device, or for otherwiseallowing the tissue sample to be collected. The sidearm 20 is preferablydisposed adjacent to the proximal end 12 a of the device 10, and itpreferably extends in a direction substantially transverse to thelongitudinal axis L of the tube 12. The sidearm 20 can optionally becoupled to the outer tube 12 by a second tube 21 that extends around aportion of the outer tube 12 and that is attached to the sidearm 20. Thesidearm 20 includes an inner lumen 20 c that is in communication withthe inner lumen 12 c of the tube 12, such that all material flowing intothe distal end 12 b of the tube 12 and through the inner lumen 12 c ofthe tube 12 will enter into the inner lumen 20 c in the sidearm 20,rather than exit through the proximal end 12 a of the outer tube 12. Thedistal end 20 b of the sidearm 20 can include a connector 22 formedthereon for mating with an entry port formed in a tissue collectiondevice, which will be discussed in more detail with respect to FIG. 6.The connector 22 can have virtually any configuration depending on thetype of tissue collection device that the sidearm 20 is adapted to mateto, but the connector 22 should preferably provide a fluid-tight sealbetween the sidearm 20 and the tissue collection device. The sidearm 20can also be used to create a vacuum within the device 10 to draw tissue,and any fluid collected with the tissue, through the device 10. Thevacuum source can be part of the tissue collection device, or optionallya separate vacuum source can be provided to mate with the sidearm 20. Aperson skilled in the art will appreciate that the vacuum source cancouple to any portion of the outer tube 12, and that the outer tube canhave a variety of other shapes, but it should at least be effective toretain a tissue sample therein.

The device 10 can also optionally include an outer housing 26 thatextends around a portion of the proximal end 12 a of the outer tube 12,and the sidearm 20, to facilitate handling of the device 10. The outerhousing 26 can have virtually any shape and size, but it is preferablyadapted to fit within a user's hands. In an exemplary embodiment, theouter housing 26 can include a rotating member 26 a formed on a distalportion thereof for allowing rotation of the outer tube 12. As shown,the rotating member 26 a is rotatably coupled to the housing 26, and itis positioned around and attached to the outer tube 12. As a result, therotating member 26 a can be used to control the position of the distalend 12 b of the outer tube 12, thereby facilitating the proper placementof the distal end 12 b of the outer tube 12 on a tissue surface. Therotating member 26 a is preferably rotatable in a controlled fashion,rather than freely rotatable, such that the position of the outer tube12 can be maintained during use.

Referring back to FIG. 1B, the device 10 further includes an inner shaft14 that is disposed within and extends through the outer tube 12. Theinner shaft 14 can also have a variety of shapes and sizes, but it ispreferably a generally elongate cylindrical member having a proximal end14 a and a distal end 14 b. The proximal end 14 a of the shaft 14 canextend out of the proximal end 12 a of the outer tube to couple to adriver mechanism 22 that is effective to rotate the shaft 14. Virtuallyany driver mechanism 22 can be used to rotate the shaft 14. As shown inFIG. 1A, and partially shown in FIG. 1B, the driver mechanism 22 is inthe form of a motor (not shown) that is disposed within a housing. Themotor, e.g., a drill or electric motor system, is effective to rotatethe shaft 14. The driver mechanism 22 is preferably only mated to theshaft 14 such that the driver mechanism 22 is movable with the shaft 14between the proximal and distal positions. In an exemplary embodiment,the motor is preferably operated at a speed that is in the range ofabout 100 rpm to 5000 rpm. Relatively low operating speeds are preferredto reduce the risk of causing damage to the tissue sample. A personskilled in the art will appreciate that virtually any driver mechanismcan be used, and that the speed of the driver mechanism can varydepending on the intended use.

The proximal end 14 a of the shaft 14 also includes a trigger mechanism24 that is effective to move the shaft 14 between the proximal anddistal positions. While the trigger mechanism 24 can have a variety ofconfigurations, FIGS. 1A and 1B illustrate a trigger mechanism 24coupled to the outer housing 26 that is disposed around a portion of theouter tube 12. The trigger mechanism 24 is pivotably disposed within theouter housing 26, and it is coupled to the driver mechanism 22 by a pullrod 25. As a result, when the trigger mechanism 24 is actuated, e.g.,using one's finger, the trigger 24 rotates the pull rod 25 to pull thedriver mechanism 22 in a distal direction, thereby causing the drivermechanism 22 to move the shaft 14 to the distal position. The shaft 14preferably moves a distance sufficient to allow only a portion of thedistal end 14 b of the shaft to extend out of the outer tube 12, as willbe discussed in more detail below.

In order to allow the shaft 14 to return to the proximal position afterthe trigger mechanism 24 is actuated, the device 10 can include abiasing element that is effective to bias the shaft 14 to the proximalposition. The biasing element can have a variety of configurations, suchas, for example, a spring 28, and it can be coupled to the triggermechanism 24, the driver mechanism 22, and/or the shaft 14. As shown inFIGS. 1B-2B, the spring 28 is disposed around the proximal end 14 a ofthe shaft 14, and it is positioned just proximal to the proximal end 12a of the outer tube 12. A portion of the spring 28 can optionally bedisposed within a second tube 21 which extends around the proximal end12 a of the outer tube 12 to mate the sidearm 20 to the outer tube 12.

In use, the spring 28 is compressed between the driver mechanism 22 andthe outer tube 12, thereby creating a biasing force that is effective topush the driver mechanism 22, as well as the inner shaft 14, back intothe proximal position. The spring 28 is also effective to create a hardstop between the driver mechanism 22 and the outer tube 12, therebylimiting the distance that the inner shaft 14 can extend from the distalend 12 b of the outer tube 12. In an exemplary embodiment, the shaft 14moves a distance, between the proximal and distal positions, that is inthe range of about 1 mm to 5 mm, and more preferably about 3 mm. Aperson skilled in the art will appreciate that a variety of othertechniques can be used to move the shaft 14 between the proximal anddistal positions.

The distal end of the inner shaft 14, which is adapted to extend fromouter tube 12 when moved into the distal position, preferably includes atissue harvesting tip 16 that is adapted to retrieve a tissue sample.The tissue harvesting tip 16 can have a variety of configurations, butit is preferably adapted to retrieve a viable tissue sample withouttearing or otherwise causing damage to the tissue. More particularly,the tissue harvesting tip 16 should allow for the rapid removal ofcleanly cut tissue, rather than crushed or torn tissue. By way ofnon-limiting example, FIGS. 3A-3D illustrate several embodiments oftissue harvesting tips 16 a-d that can be used with the presentinvention. FIGS. 3A and 3B each illustrate a substantiallysemi-cylindrical tissue harvesting tip 16 a, 16 b having a scallopedparameter that is effective to cut into tissue upon rotation of theshaft 14. In FIG. 3A, the tissue harvesting tip 16 a is substantiallyhollow to obtain a larger tissue sample, while in FIG. 3B the tissueharvesting tip 16 b is substantially solid and the scallops extendacross the surface to form ridges on the harvesting tip 16 b. FIGS. 3Cand 3D illustrate alternative embodiments of tissue harvesting tips 16c, 16 d. In particular, FIG. 3C illustrates a hollow cone-shaped memberhaving several cutting teeth 17 formed around and protruding above anouter surface of the cone-shaped member. The cutting teeth 17 functionsimilar to a cheese grater in that they penetrate the tissue to removeseveral small tissue samples which are collected inside the hollow cone.FIG. 3D illustrates a tissue harvesting tip 16 d that is very similar tothe tissue harvesting tip 16 c illustrated in FIG. 3C, but that has asubstantially cylindrical shape and that includes a substantiallyflattened distal end.

While the harvesting tip 16 used with the device 10 of the presentinvention can have a variety of configurations, shapes, and sizes, theharvesting tip 16 is preferably effective to retrieve a predeterminedamount of tissue. In an exemplary embodiment, the predetermined volumeof tissue, per tissue sample, retrieve by the harvesting tip 16 is inthe range of about 0.5 cm³ to 1.5 cm³, and more preferably about 0.9cm³. A person skilled in the art will appreciate that a variety oftissue harvesting tips can be used with the present invention, and thatFIGS. 3A-3D merely illustrate exemplary embodiments.

The distal end 14 b of the shaft 14 can also include a cutting member18, which is preferably disposed around the shaft 14 at a positionedjust proximal to the tissue harvesting tip 16. The cutting member 18 canhave a variety of shapes and sizes, but it is preferably effective tomacerate the tissue sample excised by the tissue harvesting tip 16.Similar to the tissue harvesting tip 16, the cutting member 18 should beeffective to cut, rather than tear, the tissue to allow a viable tissuesample to be obtained. By way of non-limiting example, FIGS. 4A-4Fillustrate several embodiments of cutting members 18 a-18 f that can beused with a device in accordance with the present invention. In general,each cutting member 18 a-18 f includes one or more blades 19 formedthereon having a particular shape, such as a rectangular shape, a curvedshape, a triangular shape, a square shape, or an irregular shape. Moreparticularly, FIG. 4A illustrates a cutting member 18 a having twocurved or C-shaped blades 19 a ₁, 19 a ₂ formed thereon; FIG. 4Billustrates a cutting member 18 b having three substantially triangularshaped blades 19 b ₁, 19 b ₂, 19 b ₃ extending from the shaft andpositioned equidistant from one another; FIG. 4C illustrates a singletriangular shaped blade 19 c that forms a cutting member 18 c; FIG. 4Dillustrates a cutting member 18 d, similar to cutting member 18 a, buthaving three curved or C-shaped blades 19 d ₁, 19 d ₂, 19 d ₃, formedthereon; FIG. 4E illustrates a cutting member 18 e, similar to cuttingmember 18 b, but having four substantially triangular shaped blades 19 b₁, 19 b ₂, 19 b ₃, 19 b ₄ extending from the shaft and positionedequidistant from one another; and FIG. 4F illustrates a cutting member18 f having two triangular blades 19 f ₁, 19 f ₂ formed thereon. While avariety of cutting elements 18 are illustrated, in an exemplaryembodiment, the cutting element is effective to macerate tissue intoparticles having a diameter in the range of about 0.7 mm to 1.3 mm, andmore preferably about 1.0 mm.

The device 10 can also optionally include a sizing screen 32, as shownin FIG. 5, that is adapted to control the size of the tissue particlesthat are allowed to pass through the outer tube 12. The sizing screen 32is preferably disposed just proximal to the cutting member 18, and itcan include several openings 34 formed therein which have a size thatpermits tissue particles having a size less than the size of theopenings 34 to pass therethrough. The openings 34 can vary in shape andsize, but in an exemplary embodiment the openings 34 have a diameter din the range of about 0.7 mm to 1.3 mm, and more preferably about 1.0mm. As a result, only tissue particles having a size smaller than thesize of the openings 34 will be allowed to pass through the sizingscreen 32. The remaining tissue particles, which have a size greaterthan the size of the openings 34, will continue to be excised by thecutting member 18 until they are small enough to pass through theopenings 34. To ensure that all of the tissue sample is excised to theappropriate size, the cutting member 18 and the sizing screen 32 arepreferably positioned substantially close to one another so that tissueparticles being held (preferably by a vacuum force) against the sizingscreen 32 will come into contact with the cutting member 18. In anotherembodiment, the sizing screen 32 can facilitate excising of the tissuesample. In particular, each opening can have an upstream edge that iseffective to cut tissue having a size greater than the circumference ofthe openings.

In use, the device 10 is connected to a vacuum source (preferably viathe sidearm 20) that is effective to create a vacuum within the innerlumen 12 c of the outer tube 12, and the distal end 12 b of the outertube is positioned against tissue surface 50, as shown in FIG. 7A. Themotor 22 is activated to rotate the shaft 14, and the trigger 24 is thensqueezed to advance the motor 22 and the shaft 14 in a distal direction.As a result, the tissue harvesting tip 16 will extend out of the distalend 12 b of the outer tube 12 and into the tissue. Since the shaft 14 isrotating, the tissue harvesting tip 16 will rotate to excise a tissuesample. As the trigger 24 is released, the biasing element 28 causes theshaft 14 to return to the proximal position. The trigger 24 ispreferably only actuated once to cause the shaft to rapidly advance intothe tissue to obtain a tissue sample. Once the sample is obtained, thevacuum force draws the tissue sample toward the sizing screen 32, wherein the rotating cutting member 18 macerates the tissue. Once themacerated particles are small enough to fit through the openings 34 inthe sizing screen 32, the particles are drawn through the inner lumen 12b of the outer tube 12, and preferably through the inner lumen 20 c inthe sidearm 20. Additional samples of tissue can be taken byrepositioning the distal end 12 b of the outer tube 12 on a tissuesurface and actuating the trigger 24 to obtain another sample. FIG. 7Billustrates a tissue surface 50 having a tissue sample removedtherefrom, and having the distal end 12 b of the outer tube 12repositioned to obtain a second sample.

As previously indicated, the tissue sample can be collected into atissue collection device. While virtually any tissue collection devicecan be used, FIG. 6 illustrates an exemplary embodiment of a tissuecollection device 40. The tissue collection device 40 generally includesa housing having an inner chamber with a tissue scaffold disposedtherein. The device 40 is effective to deposit the macerated sample ontothe tissue scaffold, and to collect and excess fluid obtained with thetissue sample. The device 40 is described in more detail in U.S. patentapplication Ser. No. 10/402,266, entitled “Tissue Collection Device andMethods,” filed on Mar. 28, 2003, and incorporated herein by referencein its entirety. The combination of the device 10 of the presentinvention and the tissue collection device 40 is particularlyadvantageous in that it allows a tissue sample to be excised, macerated,and deposited onto a tissue scaffold in a single step.

The features and other details of the invention will now be moreparticularly described and pointed out in the claims. It will beunderstood that the particular embodiments of the invention are shown byway of illustration and not as limitations of the invention. Thoseskilled in the art will know, or be able to ascertain, using no morethan routine experimentation, many equivalents to the specificembodiments of the invention described herein. These and all otherequivalents are intended to be encompassed by the following claims.

1. A tissue extraction and maceration device, comprising: an outer tubehaving a substantially open distal end that is adapted to be placed on atissue surface; a shaft rotatably disposed within the outer tube andmovable between a first, proximal position in which the shaft is fullydisposed within the outer tube, and a second, distal position in which aportion of a distal end of the shaft extends through the substantiallyopen distal end of the outer tube; a tissue harvesting tip formed on thedistal end of the shaft, the tissue harvesting tip being effective toexcise a tissue sample; and a sizing screen disposed within the outertube and positioned proximal to the tissue harvesting tip, the sizingscreen having openings with a size that prevent passage of excisedtissue samples having a size greater than a size of the openings; and acutting member disposed within the outer tube and coupled to the shaftat a position proximal to the tissue harvesting tip and adjacent to thesizing screen such that excised tissue samples prevented from passingthrough the sizing screen by the openings are macerated by the cuttingmember to form tissue samples having a size that can pass through theopenings.
 2. The device of claim 1, further comprising a biasing elementeffective to bias the shaft to the proximal position.
 3. The device ofclaim 2, further comprising a trigger mechanism connected to the shaft,wherein, upon actuation, the trigger mechanism is effective to overcomethe biasing force to move the shaft from the proximal position to thedistal position.
 4. The device of claim 1, wherein the substantiallyopen distal end of the outer tube is adapted to form a seal with atissue surface.
 5. The device of claim 1, wherein the substantially opendistal end of the outer tube is defined by an edge wall that is at anangle with respect to a longitudinal axis of the outer tube.
 6. Thedevice of claim 5, wherein the angle is in the range of about 30° to75°.
 7. The device of claim 5, wherein the angle is about 40°.
 8. Thedevice of claim 5, wherein the edge wall includes surface featuresformed thereon.
 9. The device of claim 8, wherein the surface featurescomprise ridges.
 10. The device of claim 1, wherein the cutting membercomprises at least one blade member extending radially from the shaft.11. The device of claim 10, wherein each blade member has a shapeselected from the group consisting of a rectangular shape, a curvedshaped, a triangular shape, a square shape, an irregular shape, andcombinations thereof.
 12. The device of claim 1, wherein the harvestingtip comprises a cone-shaped member having a plurality of cutting teethformed on an outer surface thereof.
 13. The device of claim 1, whereinthe harvesting tip comprises a substantially semi-cylindrical housinghaving a cutting surface formed around a periphery thereof.
 14. Thedevice of claim 1, wherein the harvesting tip is adapted to penetratetissue to remove a predetermined volume of tissue when moved from theproximal position to the distal position.
 15. The device of claim 14,wherein the predetermined volume of tissue, per tissue sample, is in therange of about 0.5 cm³ to 1.5 cm³.
 16. The device of claim 14, whereinthe predetermined volume of tissue, per tissue sample, is about 0.9 cm³.17. The device of claim 1, wherein the openings have a diameter in therange of about 0.7 mm to 1.3 mm.
 18. The device of claim 1, wherein theopenings have a diameter of about 1.0 mm.
 19. The device of claim 1,further comprising a driver mechanism coupled to the shaft and effectiveto rotate the shaft at a speed in the range of about 100 to 5000 rpm.20. The device of claim 1, wherein the harvesting tip of the shaft isadapted to extend beyond the outer tube by a predetermined distance. 21.The device of claim 20, wherein the predetermined distance is in therange of about 1 mm to 5 mm.
 22. The device of claim 20, wherein thepredetermined distance is about 3 mm.
 23. The device of claim 1, whereinthe outer tube is adapted to be coupled to a vacuum pump that iseffective to draw tissue through at least a portion of the outer tube.24. The device of claim 1, wherein the tissue harvesting tip and thecuffing member are configured such that tissue excised and maceratedremains viable.
 25. The device of claim 1, wherein the tissue harvestingtip is configured to excise tissue without tearing the tissue to providea viable tissue sample.
 26. The device of claim 1, wherein the tissueharvesting tip and the cutting member are configured such that a size oftissue excised by the tissue harvesting tip is larger than a size of thetissue macerated by the cutting member.
 27. The device of claim 1,wherein the tissue harvesting tip is configured to retrieve apredetermined volume of tissue.
 28. The device of claim 1, wherein thesizing screen has openings with a size that are configured to preventpassage of excised tissue samples having a size greater than a size ofthe openings and the cutting member is effective to macerate the excisedtissue samples to form tissue samples with a predetermined size that areallowed to pass through the openings.
 29. The device of claim 28,wherein the sizing screen and the cutting member are positioned adjacentto one another such that the cutting member can macerate tissueprevented from passing through the openings in the sizing screen.
 30. Atissue harvesting device, comprising: a handle housing having a triggercoupled thereto; an outer tube extending from the handle housing androtatable relative to the handle housing; a shaft having a tissueharvesting tip formed on a distal end thereof, the tissue harvesting tipbeing effective to excise a tissue sample, the shaft being rotatablydisposed within the outer tube and movable between a first, proximalposition in which the tissue harvesting tip is fully disposed within theouter tube, and a second, distal position in which the tissue harvestingtip extends through a substantially open distal end of the outer tube;and a cutting member coupled to the shaft at a position proximal to thetissue harvesting tip and fully disposed within the outer tube when theshaft is in both the proximal and distal positions, the cutting memberbeing effective to macerate a tissue sample excised by the tissueharvesting tip and received within the outer tube.
 31. The device ofclaim 30, wherein the tissue harvesting tip and the cutting member areconfigured such that tissue excised and macerated remains viable.